We intend to study genetic aspects of Wilms tumor, a common childhood cancer, and some of its associated clinical features. We will do this by analyzing the peripheral blood leucocyte chromosomes of previously identified patients with Wilms tumor and/or aniridia in order to determine whether interstitial llp deletions account for more instances of these abnormalities than previously suspected. Approximately 120 Wilms tumor patients from the Texas Medical Center (TMC), including the M.D. Anderson Hospital (MDAH) are available to us, as are 25 patients with aniridia. We will also karyotype tumor cells from patients with de novo or recurrent Wilms tumors that come to surgery. Leukocyte and tumor chromosome analyses will utilize G-banding techniques coupled with amethopterin synchronization to obtain maximally elongated prophase or prometaphase chromosomes. In addition, electrophoretic assays of red blood cell lactic dehydrogenase A activities will be performed to look for deletions of that enzyme's structural gene locus. We have already shown that locus to be near the llp13 region, which, if deleted, leads to the aniridia-Wilms tumor association.